up:: [[Statistics MOC]] Tags:: # Frequency Graphs Frequency graphs display x values with their corresponding frequencies. ### Frequency table Frequency tables simply display x alongside its corresponding frequencies. ![[Pasted image 20220928163946.png]] ### Grouped frequency table Grouped frequency tables are often used if there are too many x values for it to be reasonable to plot all of them individually. It's important to remember when creating grouped frequency tables that we have to use real limits for boundaries meaning. This means on this table the real limits for the 50-54 group would be 49.5 to 54.5. ![[Pasted image 20220928164019.png]] What are the five guidelines for creating frequency distribution graphs? 1. There should be about 10 intervals. 2. Intervals should be split in easy to read numbers. 3. The bottom score in each interval should be a multiple of the width 4. Each interval should be the same width distance apart. ==positively== skewed distributions have data clustered around the left side of the distribution where as ==negatively== skewed distributions have data clustered around the right side of the distribution. <!--SR:!2022-09-02,4,270!2022-09-02,4,272--> What is the general four step process of interpolation: 1. ==Find the width of the interval on both scales.== 2. ==Locate the position of the intermediate variable on the whole scale. This position corresponds to the fraction of the whole interval.== 3. ==Use the same fraction to determine the corresponding position on the other scale by multiplying it with the width of the other scale.== 4. ==Use the distance from the top to determine the distance on the other scale.== ^c090f4 <!--SR:!2022-09-01,3,252!2022-09-01,3,252!2022-09-01,3,254!2022-09-02,4,274--> Percentiles and percentile ranks are used to describe the position of individual scores within a distribution. ==Percentile== rank gives the cumulative percentage associated with a particular score. A score that is identified by its rank is called a ==percentile==. <!--SR:!2022-09-01,3,254!2022-09-02,4,274--> ### Rstudio ### How to plot a histogram: You plot a histogram using the hist() function. First you put the vector, then the main (title of the graph), then the labels for the y and x axis, then the boundaries you are using for your graph, and finally the color you want to use. Example histogram: hist(NationIncomes$Transania, main="Histogram of Transanias Kiloguiders", xlab="Kiloguiders", ylab=NULL, Bndrs, col="green") ### How to create boundaries Boundaries are created using the seq() function. The first number is the start of the boundary, the second is the max, and the third is the interval. Example boundary: Bndrs = seq(0, 115, 5) ___ # Resources